Dear Developers,
I am Md. Zaved Khan, my call sign is S21ALT, yesterday on 18/12/2025 while updating my node number 59890, I got the message, (Please enter a valid ITU-format amateur radio callsign). But our country's amateur radio operators use the call sign starting with S21 which is not mentioned in ITU website and the Civil Aviation Authority callsign starts with S2 which is mentioned in ITU website. I haven't had such a problem in the past but after updating your website I am facing this problem, the matter is very important. The amateur radio license authority of my country is "Bangladesh Telecommunication Regulatory Commission" (BTRC), providing s21 prefix callsign to more then 1000 amateur radio operators in Bangladesh . I have attached my amateur radio operator's license, I am specially requesting you to resolve the above issue. Such as adding s21 prefix in your database as amateur radio operator Callsign of Bangladesh . Thank You
